What an interesting statement. The manufacturers don't want these repaired. We are facing an environment crisis, that we may not recover from, and these companies promote waste. This has to change and very soon. I appreciate more than ever the quality electronics from the 1970's and 1980's. A person such as yourself could fix almost any electronics from this era. God bless.
Agree there are speakers tube amps turntables from way back when that out last morden day equipment. FACT another thing is how you use and look after it can play a major part also. Im lucky my home cinema i put together in 2012 is all in perfect working order. And was not cheap £8000+ made me give it that loving touch 😂😂😂
Sadly, you're correct and this is the case on almost every product. Even basic ones. I bought a manual can opener that cracked the very first can I tried to open.
It's true but hdmi arc is convenient to have, and room correction etc. It's sound united setting the trend for expensive electronics to be junk in reliability just to save a buck.
I tried explaining this fact about the environment to David Pogue and Scientific American, unfortunately, they are too tied up in their politics to examine reality.
Hi Dave, I just want to thank you for all that you do on your channel. By following along with your troubleshooting procedures I was able to fix my Yamaha A-S500 amplifier yesterday with an intermittent output on the right channel. I tracked it down to one of the protection relays and after re-flowing the solder connections it now sounds as good as when it was new. Keep the repair videos coming! :)
Problem is, if any company were to try to break out of the race to the bottom, and make their receiver 25% more expensive than their competitors on the basis that it was service-friendly, they'd end up losing all their market share. Don't blame Denon, blame the buying public. The companies that wind me up are the ones who do charge more than anyone else for the same thing and *still* make their products unfriendly to service. Apple I'm looking at you.
I have actually seen this same stuff and I am pretty sure it was solder resin used during assembly... it is almost the same as that circuit glue you have talked about ... over the years it becomes conductive... thus triggering the protect circuit ... I have a neighbor that had one for approximately 15 years and it was triggering the protect circuit... cleaned the entire board with isopropyl alcohol removing the solder resin used during the manufacturing process... and just to make sure re-flowed the output transistors... no more circuit protection kicking in ... I suppose after washings during production the solder rinsing fluid becomes too saturated with resin to fully clean the resin and over time it becomes conductive enough to trigger the protection circuit in all honesty I believe that was the problem and that's the crud you saw ... I am not certain but I think the power transistors are solder by hand and they don't clean the resin afterwards... and over the years it becomes conductive enough to trigger the protection circuit to activate... my neighbor's unit functions perfectly... during the cleaning the resin was very brown as it was absorbed by the old towel if I understand correctly the resin is a very mild for acid to clean the surfaces as they are soldered in place and that explains why it becomes slightly conductive as time passes... I recently had the same trouble with my computer board ... it wouldn't even POST (power on self test) prior to that I had a hard drive (4 total) that Windows kept popping up messages cache couldn't be read data maybe lost ... and it would disconnect from the drive completely.... after I did the same method cleaning the entire motherboard it has not given any messages about not being able to read cache from or to the drive and it posts EVERY TIME NOW as well ... I am very convinced that the traces of solder resin will cause problems over time... most devices these days use EXTREMELY small current signals that can be wiped out or at least be undetectable not to mention how the tiniest currents these signals push through to other chips and circuits anyway hope this helps someone that can't find any bad components yet the device still won't work correctly
@@12voltvids haha, my man ! :)) ( i love watching your videos, thank u for your patience and time for explaining step by step all the electrotechnics involved, it amazes me u cleverly and logically know ur "circuits" pretty well sir !
@@Mihai092 truth be known I have forgotten much of it. I left the repair business in 2003 and went into a totally different industry. When I left I promised myself I would never work on electronics again. Managed to stay away for 9 years. Picked up the soldering iron as a favor for a friend and made a stupid video of the repair and put it on RU-vid and the rest is history. Seems that there are a few people that still want to fix their old units and I have enough stuff of my own I have collected to keep me busy on my days off.
@@12voltvids i can imagine why u left, or at least i guess, im an Electrician myself but working within a 0.08/10kv electrical substations that powers up the tramway, transforming and lowering high currents from AV to DC, machines that acts like a big switch in case of overload to a certain amp 1500-2000. Not so much minimal electrotechnics in there, maybe on the automatic side of it and protections, relays, auxiliar side, batteries, etc, in rest more mechanics but i like that too.. i like doing stuff with my hands, i wouldnt imagine myself sitting in a chair not being in a team, working.. socializing, laughing. Im really noob in soldering, i first picked up the soldering iron when i was 8, i saw my dad repairing my nintendo ( he's an electrician too ) and i wanted to be like him ( ended up wrecking the gamepad that was trying to repair ).. since then i always had this passion for electronics. I just wish he would had/ share this kind of ur kindness, patience, approach and passion towards letting me know stuff when i was all over him.. i was always eager to learn but i guess he was too tired by this society. Anyway sorry for writing so much personal stuff and bad english :)) , u seem like a really kind man. Would ask for 1 more minute of your time, what do you think of nowadays Denon build quality, maybe compared to other receivers expecially on the low-entry.. i plan to buy a receiver for a 7.1 setup, i guess u saw some stuff opening so much cases :)) Thanks for your time and your response !
Reason they make them so hard to work on? It's all about the $$$$. Either pay tons of money to have it repaired, or replaced. Such as everything today. Give me the old mechanical washers and dryers. And other appliances. Toothbrushes are amazing. I use them to clean fan grills that I cannot submerge in soapy water. Because the motor and wiring is attached. Just a damp toothbrush or paintbrush.
I have a Goldstar brand amp that I assume is from the mid-80s. I picked it up because I liked the looks and it was just a buck. It has a 1.5 amp fuse inside that looks like it got a little too tired one day. No smoked glass though. It also has a whopping 15 amp fuse that I popped when I flip the voltage switch to 240. The power transformer made an interesting hum before the fuse went
Nice one. I had the lid off my Denon AVR-E400 a few weeks back investigating an issue.. Even worse to disassemble- the HDMI digital input board was connected to two other boards with multi pin connectors in a few different positions.. making a sort of "cube" of hard-connected boards.. what a pain. Their remote control app is garbage too, not buying Denon again. Going to replace the thing soon.
Dave, i feel really sorry for you as i repaired the same unit back in 2015 and i hated the design :-( On mine, one channel had blown up taking nearly every part connected to the output transistors, and the output transistors. After re assembly the bias was checked and it was spot on. Sounded smashing, but i didn't want to see one again lol.
Well done. The PDFs of most service manuals for Denon (Pioneer, Onkyo, etc) A/V units are readily available on the internet. These units usually offer a diagnostic mode that will display a message or give a code for the type of fault shutdown (DC voltage, short circuit over current, etc). By studying the schematic, you can narrow down to the faulty block or component. The various power feeds can be disconnected which can help isolate the problem down to a specific board, e.g. remove power from main amp board and unit powers up OK means the fault is on the main amp board. There may be safety interlocks between boards - so this method may not always work.
My Onkyo preamp has the same mess inside. It gives me the feeling that those units are patched up with new features over and over and over again year after year, never seeing a proper re-design.
I have a Denon 1908 that had gone into fault and the client just told a colleague to take it away! The coaxial feed from a Skybox at the head end wouldn't work via a converter. Skyboxes used to only have full surround from their digital outs. Long story short - it finally landed in my lap after everyone else had given up (It was an AV installer company with no repair engineer). It just needed a factory reset!! I still have it as my home cinema set up. I had an issue a few years back in which it literally Screeched at a high level, moving the input leads cleared it. When I had lot's of time I decided to re-solder them, but they were fine! But then I saw that a Single strand of speaker wire was touching the main body, I changed to Banana plugs and it's been great ever since! These designers go to the pub each night and come up with more creative ways to make equipment non serviceable. And have a good laugh, no doubt. Unfortunately - the last laugh is Ours! Well done!!
Just wait until the next generation is made all of glass and glued together like a cell phone lol Think that stuff on the output transistor was from hand soldering with a organic flux?
Are Denon non good brand😂…I will just get a Sony brand avr…I used to have old one north of 1K even the Denon t($1400)hat just died…but the displays for every unit are operationally working…but no sound on my fancy speakers sub surrounds…Big Boses…etc😅
Love your perfect diagnosis for every fault, good work. I have a demon avr 4308 no sound form speakers but every other thing works alright. Please do you have a solution? Thanks.
I’d hate to think how many screws I’d have leftover after putting that thing back together. Absolutely ridiculous how modern kit is constructed in such a way as to make DIY repairs either impossible or awkward to the point of wanting to throw the bloody thing across the room and out the window; the consequence of which being an expensive item is likely to end up as a very ugly door-stop unless you can DIY or have access to a technician willing to do repairs at a price that is finically viable (ie less than the cost of replacing the unit in question)!
Ugly, bulky, and broken, yet the mad lad tries to fix it, most Americans would throw it out and buy a new one This actually would be an exeption cause it is pretty trash
You're scaring me into not buying denon, marantz, yamaha, and we know anthem is probably in there. What is left under 3k? I need hdmi ! I'm using an old outlaw av preamp and I need to upgrade.
Good job. Sony receiver had a similar design. To deoxit 2 tone controls had to remove many screws, pull off the front panel and remove 2 circuit boards and disconnect 2 connectors just to get to them.
I really enjoy and have learned a lot from your vids Dave. I have an 1803 on the bench right now...easy diagnosis as the previous owner shorted the center channel and blew the output transistors...The darlington is being replaced too because it is out of tolerance, but couldn't find the OEM, so I had to research for an equal...pain in the butt! At least taking the boards out gave me an excuse to completely clean the unit.
Denon is one of those brands I hate to work on. I currently have one on my bench with a blown L channel, usually in that case I'll recommend a full upgrade of the output and bias transistors based on the latest service bulletin. Overall extra cost of parts and little extra labour involved make it an easy sell if it will last longer.
nice! that looks really similar to mine though mine has alot more daughter boards to remove :) mine has been working fine for quite a long time, now that it is in an enclosed cabinet I am going to put a exhaust fan over it (the back of the cabinet is open. hopefully that will keep things from getting too hot. great video thanks for sharing!
great job as always each video is a new adventure with great gear and the end result is always the same you make the gear like new thank you for sharing this
I check for obvious bad solder connections and then move onto power supplies. Usually power supply problems are traced to missing voltages, not over voltages.
Practice visual acuity technique then clean and retest . Take pics as you go . Note that resistors that measure 2k and are labeled R115FR doesn’t mean it is a fusible resistor . The FR means front right output circuit. Check me on this assessment of my Denon AVR-2105 repair.
I would check the amperage draw through the fusible resistors and on the 5V Circuit as well just to make sure nothing is getting too hot through them or there is not a partial short or anything causing that circuit to draw too much current. There is a reason why those resistors failed.
The source of all problems it the EU's lead free solder requirements, it is junk and as a former solder process engineer, it never lasted 25 % as long as leaded solder. One failed solder joint starts the ball rolling. If you think about it , some of the chips have nearly as many solder joint as a radio in the old days.
Yes I am fully aware of red-free soldier and how bad it is. When I was still working in the business Sony came out with a requirement that we use low lead solder for repairs. Conventional solder was 60/40 low lead 63/37. They didn't want us using lead free because as they put it that free was too difficult to work with to get a reliable connection in the repair business and they had found from their own internal testing that even their own internal techs we're having a hard time with it. even the 63/37 is more difficult to work with and that's just a 3% difference. No thanks I'll stick with 60/40. There's actually another type of solder which had a higher than concentration and it was soft it was low melt temperature solder which was nice it was quite malleable. I believe the modern lead free it's probably a little better than when it first came out but that first generation was horrible stuff
My workshop will get clean when all the people that bring me their valuable vintage electronics actually come and pick their crap up before i throw it out. I have more stuff around here that is fixed and ready for pickup and the owner contacted and they just never come to get it.
@@markanderson350 _"They have a commercial division and people think consumer is similar but its not."_ True, but Denon did turn out some really good stuff in the 80s, 90s, and early 2000s. But their quality has been taking a nosedive recently, from engineering to parts choices. Denon simply doesn't make them like they used to.
These modern surround sound receivers are hard to work with, and are not very reliable in general as they get older: they seem like the most common broken item in any household. This brings me to a problem I have been having with my early 2000s Onkyo 5.1ch receiver, the TX-SR500. Here’s the issue. It seems that around 1/4 of the times I turn it on, the rear left channel does not engage right away. When this happens, I usually have to tap on the woofer cone of the speaker on that channel. This is annoying, because I happen to have speakers with non-removable grills: the grill fabric is just stretched over the front baffle, with the drivers mounted from the inside! (Sound familiar? Yup, they’re Paradigm atom V2s. Refoamed, of course.) I can only barely touch the surround of the speaker through the grill. If the channel still does not power up, the next thing I do it press the “speakers A” button around 10 times in rapid succession, then go back to tapping the cone. This usually always fixes the issue. Is this a fixable problem? What do you think it might be? Does this sound like a capacitor? A resistor? A bad solder? A lost cause??? If I get a new receiver, what do you recommend? Yamaha? Marrantz? Denon? Another Onkyo? (This is my second Onkyo to have a problem. The first one was worse, it just acted like it wasn’t even plugged in. It was. I checked.) I will probably buy an older used product, to save money and materials. They usually work fine. My research has led me to believe that Yamaha lasts longer, but might be less clear with more midrange sound.
I tought that too but it will be ugly, those regulators cost cents, even cheaper than a transistor it self. With regulator it will look like factory made
@@12voltvids here in my country this will be USD 0.25, wich is cheaper than 1.5A transistor, and still you will need a zener, couple resistors and a cap and a spider web ;)
Great vid. Big thanks. Just hoping my vintage AVC-A1XVA monster that I have had for nearly 13 years doesn't fail like this. At 44kg, It's too heavy to lift !
Thank you and what I did rather than taking the whole thing apart which looks like a major pain in the ass is I took a small Dremel saw and dremeled a little square hole out on the bottom and just worked on it from within that hole which was so much easier and now my receiver works great
Hi there, 14 mins in and paused to write this comment as I have a Denon AVR-1910 which powers off after a 10-20 seconds with a blinking red power standby led, 0.5 sec intervals. Manual says either speaker / speaker connection issue or amplifier circuit has failed. I'm assuming the latter as I have disconnected all speakers and removed speaker cables, just powering the unit up with nothing connected and it does the same. When my speakers were hooked up I would get buzzing / interference sound start coming from them and then after a few seconds it would switch off and go into this blinking red power led phase. Hoping that this video will help direct me find the fault! I'm no expert at all, I don't know what resistor values should be should I need to check them but I have my trusted multimeter and have good experience with soldering (misspent youth chipping / jtagging consoles :-)) Seeing you move from the solder pump to the braid, lol, I can relate! I've never had a solder pump that can outdo the braid, they just aren't powerful enough when you can't get a snug fit up against the joint. PS: You don't use any flux I notice?
Hi there, I have a brandnew Marantz SR7015 and it shuts down on me. It’s not heat management , I replaced the wires, the ARC hDMI cable , and and factory reset , after factory reset it holds up for 2 hours and then it goes to protection mode , any idea ? Appreciate any info .
I literally had exactly the same amp (but in silver) on my bench this morning with exactly the same fault..... I thought that I would give it a go and look at that same board. I managed to get it out by just removing the speaker output board and 3 screws from the back then the cables and the four screws holding the board in place..... JACKPOT, the 7815 had literally blown itself to pieces. Having one in stock I fitted it and checked the other regs and all were fine. Feeling well pleased with myself (as I got the amp for free!) I re-assembled it and switched it on. It powered on and I waited.... It seemed to be ok then shut down just as it had originally. I removed the board again and all the components are still OK. Oh well you win some you lose some. Nice video. Now the big question is can I be bothered delving into this amp or not 🙂
Not long purchased a Sony STR-K870P when i power it up the thing like a sound with some vibration for about 1 sec, anyone know if this is normal - But hey 12volt! another top video - more tape please!
Okay so I have a similar unit. Has 4 power regulators on the heatsink. 15 pos, 15 neg, 12 and 5 volts. I replaced the 15 pos but still have the same problem. Looking at your technique for bypassing the regulator. Can you explain in a bit more detail how to do that. What are the connections and what power do I need. Thx
A +20v and -15v supplies on an opamp do not affect its linearity, assuming 35v across the device is not beyond the abs max rating. They can be different voltages, it only makes the output stage clip asymmetrically. The input stage uses current sources to bias the input transistors so they don’t ‘feel’ the supply voltages (unless they’re very low or beyond abs max). Also I doubt there’s any sophisticated fault detection on the +/-15v rails. Maybe a basic min voltage check. It’s possible the 7815 output is shorted to the input. I wonder what those 2 ohm (0.22 ohm?) resistors are for. They’re not feedback resistors bc you have fixed regulators. Are there 2 positive regs? Current sharing resistors?
HELP, PLEASE. I am working on one of these with the same layout and the same symptoms. I replaced the same resistors. The problem is that there is not enough voltage getting to the 15 and -15 regulators, its like 2volts. The diodes check out good. Any suggestions??? FYI, love the channel. Great videos!
I picked one of these up at my local goodwill yesterday. It is doing the same thing. How difficult would it be for someone who has never done anything like to see if the cause is the same and if so do the repair?
@@12voltvids I do not but it would be a good idea for me to get them since I sell video games and being able to replace dead batteries on old pokemon games would be a good thing for me to be able to do.
That crud surrounding the hand soldered connections is no clean flux. Most manufacturers will still wash it off their products, at least the IPC 610 rev. Class 3 assemblies. This product is somewhere in between Class 1 and 2.
Hi Dave, great video! I have an AVR-3312ci that is doing essentially the same thing. Power on, green flash every second for a-few seconds, then it "reboots" and does the same thing. No red ring though, it's always green, and the diagnostic menu shows "NO PROTECT" in the protection history. This unit seems to be a-bit of an older design than the AVR-2307 (different board layout, etc). Do you think the power supply regulators could be the issue with the AVR-3312ci also?
After seeing my amp taken apart like that , I'd rather buy a new one lol. I'm very fortunate that my denon x4000 and denon 3313UD still looks brand new always have left on stand by not to kill capacitors and always covered when not in use. If I'm lucky i get to watch a movie or two once a week thanks to work and family life another thing that's saved it for so long.
I have a different take on the AVRs. Indirectly we the consumers are to blame for this state of affairs. Let me put it this way. We want more and more complexity put into a single box. These units have multiple functions which a stereo amp can't even imagine. It switches sources, plays radio, amplifies, decodes various formats, accepts various inputs, has an on-screen display, has setup options and other than cook an omelette for us does almost everything. Where does one find the space for the electronics to do all this? So the boards have to be sandwiched as space inside is a premium. I don't blame the manufacturer but the consumer who keeps on wanting more for less.
i bought an iron of aliexpress. but got the 110v for 220v. oh baby that tip glows bright orange.Thanks for vid. it seems you got lucky getting to those blown resistors real quick. It's like you have another special sense. nice one.
Wow. that much disassembly looks like a nightmare. I have a Denon that one channel is not working. I think it is probably cheaper to buy a new unit. This one is 6 years old. I have to assume that the cost of all that work would be more than half of what a new unit would cost, (assuming about $500 is my budget.) Great work and patients. You are a master electronic technician.
